Such slip-form pavers are required for making concrete road surfaces. Known slip-form pavers comprise a tractor consisting of a machine frame and four track assemblies carrying different working means for spreading and smoothing the concrete.
Since the desired width of the concrete lanes can vary, for example at merging lanes, a rearrangement of the slip-form paver is often required which can take a restructuring time of two to three days depending on the necessary extent of the restructuring work.
Such interruption of the work is undesirable so that slip-form pavers have been developed which have machine frames that can the widened telescopically (WO95/28525, WO97/04176).
While it is relatively simple to change the frame width of the machine frame telescopically, severe problems may arise if at the same time also the working means have to be telescopically changed in the working width.
From DE-A-198 14 052, it is known to mount the machine frame with a transverse rail guide having at least two telescopically movable rails, and that a carriage for a working means is movable in the transverse direction on the rail guide. Such a device allows for the displacement of a working means over the entire working width, with no restructuring work required even when the working width is altered.
The carriage has a plurality of rollers with parallel adjacent running grooves corresponding in number to the number of rails so that at least one of the running grooves engages one of the rails. In this manner, the track assembly may be displaced over the entire working width regardless of the working width set.
It is a disadvantage of the known solution that, due to the subdivision of the rail guides in the transverse direction, the rigidity for the track assembly is not sufficient, when great forces are exerted through the working device mounted to the track assembly. Moreover, the transition from one rail element to the next rail element prevents the guiding of the carriage from being continuously stepless.
Therefore, it is an object of the present invention to improve a slip-form paver of the type mentioned above such that a working means is displaceable in a stepless manner over the entire working width in a direction transverse to the traveling direction with a great rigidity of the longitudinal guide.